Amplifier arrangement and method for the compensation of a signal component in an amplifier arrangement

Abstract

An amplifier arrangement having a first amplifier stage and at least one second amplifier stage is provided, an input of the second amplifier stage being connected to the output of the first amplifier stage. The first amplifier stage and also the second amplifier stage are in each case designed for amplification with an adjustable discrete gain factor. Furthermore, provision is made of a feedback path connected between the output of the at least one second amplifier circuit and the input of the first amplifier stage. The feedback path is designed for generating and outputting a signal to the input of the first amplifier stage for the compensation of an offset signal at the output of the at least one second amplifier stage. Said offset signal is brought about by a setting of the gain factor of the first and/or the second amplifier stage.

1 . An amplifier arrangement, comprising: 
 a first amplifier stage having a first adjustable discrete gain factor and having an input and an output;    at least one second amplifier stage having a second adjustable discrete gain factor and having an input connected to the output of the first amplifier stage and an output; and    a feedback path connected between the output of the at least one second amplifier stage and the input of the first amplifier stage, wherein the feedback path generates and outputs a signal to the input of the first amplifier stage, wherein the signal compensates for an offset signal at the output of the at least one second amplifier stage brought about by a setting of the first adjustable discrete gain factor and the second adjustable discrete gain factor.    
   
   
       2 . The arrangement of  claim 1 , wherein the first amplifier stage further comprises an actuating input that receives an actuating signal that sets the first adjustable gain factor.  
   
   
       3 . The arrangement of  claim 1 , wherein the at least one second amplifier stage further comprises an actuating input that receives an actuating signal that sets the second adjustable gain factor.  
   
   
       4 . The arrangement of  claim 1 , wherein the feedback path comprises an integrating circuit.  
   
   
       5 . The arrangement of  claim 4 , wherein the integrating circuit comprises a charge store that sets an integration constant.  
   
   
       6 . The arrangement of  claim 4 , wherein the integrating circuit comprises a filter with an adjustable frequency range for setting an integration constant.  
   
   
       7 . The arrangement of  claim 4 , wherein the integrating circuit comprises a differential amplifier and a charge store, coupled to the differential amplifier.  
   
   
       8 . The arrangement of  claim 7 , wherein a capacitance of the charge store is adjustable.  
   
   
       9 . The arrangement of  claim 7 , wherein the charge store comprises varactor diodes connected in parallel.  
   
   
       10 . The arrangement of  claim 1 , wherein the first amplifier stage comprises a series connected low pass filter.  
   
   
       11 . the arrangement of  claim 1 , wherein the arrangement is formed in a semiconductor body as an integrated circuit.  
   
   
       12 . An amplifier arrangement comprising: 
 a low noise input amplifier that amplifies an input signal according to an adjustable gain factor.    a frequency conversion component that converts the input signal to a baseband signal having a baseband frequency;    a summation component that combines the baseband signal with a feedback signal;    a plurality of cascaded programmable amplifier stages that selectively amplify the baseband signal to provide an output signal; and    an integrator circuit that processes the output signal to obtain the feedback signal.    
   
   
       13 . The arrangement of  claim 12 , wherein the adjustable gain factor of the low noise input amplifier is selected to obtain a desired signal strength prior to conversion by the frequency conversion component.  
   
   
       14 . The arrangement of  claim 12 , wherein the baseband signal has a quadrature and in phase component.  
   
   
       15 . The arrangement of  claim 12 , wherein at least one of the plurality of cascaded programmable amplifier stages comprise a programmable amplifier and a low pass filter connected in series.  
   
   
       16 . The arrangement of  claim 12 , wherein at least one of the plurality of cascaded programmable amplifier stages comprise a programmable amplifier.  
   
   
       17 . The arrangement of  claim 12 , wherein the plurality of cascaded programmable amplifier stages have a plurality of associated gain values selected to obtain a desired gain for the output signal.  
   
   
       18 . A method for the compensation of a signal component in an amplifier arrangement, the method comprising: 
 providing the amplifying arrangement comprising at least two series-connected amplifier stages having adjustable discrete gain factors;    applying a signal to an input of the amplifier arrangement;    changing a gain factor of at least one of the at least two amplifier stages to compensate for a signal component; and    generating the signal component from an output signal of the arrangement and feeding back the signal component to the input of the arrangement.    
   
   
       19 . The method of  claim 18 , wherein generating the signal component comprises integrating the output signal with an adjustable time constant and subtracting the integrated signal component from the integrated output signal.  
   
   
       20 . The method of  claim 18 , wherein changing the gain factor occurs on the signal component having an amplitude less than a threshold amount.